今年，大寒小寒谁更寒？

Core Viewpoint - The current winter season is experiencing unusual weather patterns, with a warm period followed by a strong cold wave, leading to expectations that this year's "Dahan" (Major Cold) may be colder than "Xiaohan" (Minor Cold) [1] Group 1: Weather Patterns - This winter has shown a rare "warm background" prior to the cold wave, with significant temperature increases during Xiaohan, where many weather stations broke historical records for mid-January temperatures [1] - For example, on January 15, about 10% of national weather stations set new records for mid-January, with over 100 stations breaking historical records for the month [1] - In Hefei, Anhui, temperatures exceeded 20°C for three consecutive days, an unprecedented occurrence for this time of year [1] Group 2: Regional Temperature Variations - Different regions are experiencing varying temperatures; northern areas like North China and Northeast China are expected to become colder during Dahan, while southern regions like Jiangnan and South China will see only slight temperature increases [2] Group 3: Long-term Climate Trends - Long-term meteorological data from 1991 to 2020 indicates that "Xiaohan is colder than Dahan" is the norm, with average temperatures during Xiaohan reaching a low of -5.0°C, compared to -4.5°C during Dahan [3] - This trend has been stable since systematic meteorological records began in the 1950s, with the exception of the 1970s when Dahan was slightly warmer by 0.02°C [3] - Notably, 23 provinces and regions experience colder temperatures during Xiaohan, while eight areas, including Jiangsu and Guangdong, are exceptions where Dahan is colder due to geographical factors [3] Group 4: Post-Dahan Weather Expectations - After Dahan, a warming trend is expected, with average temperatures rising to -1.9°C as spring approaches, although cold weather may still occur [4] - There is a possibility of cold wave events even after the start of spring, influenced by global warming and changes in atmospheric circulation [4] - It is advised to remain cautious and not to prematurely reduce winter clothing, as actual weather conditions should dictate clothing choices rather than relying solely on seasonal markers [4]